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Start Over Topic algorithms Topic imaging systems Publication Year Range Last 50 years
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1. Propagating-path uniformly scanned light sheet excitation microscopy for isotropic volumetric imaging of large specimens

Author

Mugen Liu, Jun Nie, Junyu Ping, Peng Fei, Fang Zhao, Dan Zhu, and Tingting Yu

Subjects
Paper, Optics and Photonics, Materials science, Optical sectioning, Light, Biomedical Engineering, Normal Distribution, imaging systems, 01 natural sciences, law.invention, optical design, 010309 optics, Biomaterials, Mice, Optics, Imaging, Three-Dimensional, law, Oscillometry, 0103 physical sciences, Microscopy, Image Processing, Computer-Assisted, Animals, Image resolution, isotropic resolution, Zebrafish, three-dimensional reconstruction, business.industry, Resolution (electron density), Rolling shutter, Laser, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, biomedical optics, Microscopy, Fluorescence, Spinal Cord, Light sheet fluorescence microscopy, business, light-sheet microscopy, Algorithms, Gaussian beam
Abstract

We demonstrate a propagating-path uniformly scanned light sheet excitation (PULSE) microscopy based on the oscillation of voice coil motor that can rapidly drive a thin light sheet along its propagation direction. By synchronizing the rolling shutter of a camera with the motion of laser sheet, we can obtain a uniform plane-illuminated image far beyond the confocal range of Gaussian beam. A stable 1.7-μm optical sectioning under a 3.3 mm×3.3 mm wide field of view (FOV) has been achieved for up to 20 Hz volumetric imaging of large biological specimens. PULSE method transforms the extent of plane illumination from one intrinsically limited by the short confocal range (μm scale) to one defined by the motor oscillation range (mm scale). Compared to the conventional Gaussian light sheet imaging, our method greatly mitigates the compromise of axial resolution and successfully extends the FOV over 100 times. We demonstrate the applications of PULSE method by rapidly imaging cleared mouse spinal cord and live zebrafish larva at isotropic subcellular resolution.

Published
2019

2. Image categorization: Graph edit direction histogram

Author

Gao, Xinbo, Xiao, Bing, Tao, Dacheng, and Li, Xuelong

Subjects
*BULK solids handling, *IMAGING systems, *ALGORITHMS, *PAPER
Abstract

Abstract: This paper presents a novel algorithm for computing graph edit distance (GED) in image categorization. This algorithm is purely structural, i.e., it needs only connectivity structure of the graph and does not draw on node or edge attributes. There are two major contributions: (1) Introducing edge direction histogram (EDH) to characterize shape features of images. It is shown that GED can be employed as distance of EDHs. This algorithm is completely independent on cost function which is difficult to be defined exactly. (2) Computing distance of EDHs with earth mover distance (EMD) which takes neighborhood bins into account so as to compute distance of EDHs correctly. A set of experiments demonstrate that the newly presented algorithm is available for classifying and clustering images and is immune to the planar rotation of images. Compared with GED from spectral seriation, our algorithm can capture the structure change of graphs better and consume 12.79% time used by the former one. The average classification rate is 5% and average clustering rate is 25% higher than the spectral seriation method. [Copyright &y& Elsevier]

Published
2008
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3. High Dynamic Range Imaging by Fusing Multiple Raw Images and Tone Reproduction.

Author

Chung Kao, Wen

Subjects
*IMAGING systems, *OPTICS, *OPTOELECTRONIC devices, *REMOTE sensing equipment, *SCANNING systems, *PAPER, *ALGORITHMS, *ALGEBRA, *FOUNDATIONS of arithmetic
Abstract

This paper presents an integrated color imaging system for taking images in extremely high dynamic range scenes. The system first fuses several differently exposed raw images to acquire more intensity information. The effective dynamic range of the image raw data can be extended to 256 times ~five differently exposed images are fused. Then it runs edge detection iterations to extract the image details in different luminance levels. The proposed tone reproduction algorithm equalizes the histogram of the extracted fine edges which tends to assign larger dynamic range for highly populated regions. Finally, the local contrast enhancement is performed to further refine the image details. The experimental results show that the proposed high dynamic range imaging system has good performance on both tone and color reproduction'. [ABSTRACT FROM AUTHOR]

Published
2008
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4. Combined ultrasound and photoacoustic imaging of blood clot during microbubble-assisted sonothrombolysis

Author

Manojit Pramanik, Dhiman Das, and School of Chemical and Biomedical Engineering

Subjects
Paper, Optics and Photonics, Time Factors, Swine, Biomedical Engineering, Photoacoustic imaging in biomedicine, Signal-To-Noise Ratio, imaging systems, 01 natural sciences, 010309 optics, Biomaterials, Photoacoustic Techniques, Surface-Active Agents, ultrasound imaging, Ultrasound Imaging, 0103 physical sciences, Medical imaging, Medicine, Animals, Thrombolytic Therapy, Photoacoustic Imaging, Ultrasonography, Microbubbles, business.industry, Ratio value, Heparin, Ultrasound, Chemical engineering [Engineering], Water, Thrombosis, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Signal-to-noise ratio (imaging), Special Section Celebrating the Exponential Growth of Biomedical Optoacoustic/Photoacoustic Imaging, sonothrombolysis, Local environment, blood clot, photoacoustic imaging, business, Preclinical imaging, Algorithms, Biomedical engineering, circulatory and respiratory physiology
Abstract

Blockage of healthy blood vessels by blood clots can lead to serious or even life-threatening complications. The use of a combined ultrasound (US) and photoacoustic (PA) imaging was explored for blood clot monitoring during microbubble-assisted sonothrombolysis. PA imaging is an emerging hybrid imaging modality that has garnered the attention of the biomedical imaging community in recent years. It enables the study of the composition of a blood clot due to its sensitivity toward optical absorption. Here, in vitro imaging of the side of a blood clot facing the microbubbles was done over time. The US and PA signal-to-noise (SNR) ratio value changes during microbubble-assisted sonothrombolysis were studied for two different local environments: blood clot in deionized water and blood clot in blood. In the first case, US and PA SNR values increased by 4.6% and reduced by 20.8%, respectively after 30 min of sonothrombolysis treatment. After 10 min of sonothrombolysis treatment of the blood clot in blood, the US and PA SNR values increased by 7.7% and 38.3%, respectively. The US and PA SNR value changes were recorded in response to its local environment. This technique can be used to determine the final composition of the blood clot which may, in turn, help in the administration of clot-dissolving drugs. MOE (Min. of Education, S’pore) Published version

Published
2019